the rims i have on my G for winters fit on the sport model and the non sport model.
and the big brakes are the same as the G37 sport model.
and they are the same size all around, 18" and 225/50/18
check this link over at myg37.com
For Sale Winter package for sale!! - MyG37
it isnt sold yet either, it's the same ones i have.
i bought from Tire rack.